A dual-induced self-expandable stent based on biodegradable shape memory polyurethane nanocomposites (PCLAU/Fe3O4) triggered around body temperature

Concerning the occurrence of in-stent restenosis and stent thrombosis of stent implantation with balloon angioplasty, a dual-induced self-expandable stent based on biodegradable shape memory polyurethane nanocomposites (PCLAU/Fe3O4) was developed. The stent could maintain its temporary shape at body temperature for a certain period of time while it was able to recover to its permanent shape at the temperature a little above body temperature (around 40 degrees C) in both a water bath and an alternating magnetic field. The trigger temperature and remote local heating ensured enough operation time and harmless activation without heating the body tissue. The nanocomposites had high fixing ratios above 99% and recovery ratios above 82% at both 37 and 40 degrees C. Cytotoxicity and in vitro degradation showed the nanocomposites had good biocompatibility and biodegradability. The PCLAU/Fe3O4 nanocomposites with dual-responsive shape memory effects, desirable mechanical properties, biocompatibility, and biodegradability show great potential for vascular stents. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45686.